Part 1 Flashcards
Describe the path of the light microscope from the light source to your eye
Light source, condenser lens, specimen, objective lens, mirror, projector lens
What does a specimen look like when using a Brightfield technique?
Little contrast in poorly pigmented cells. Passes light directly through specimen.
What does a specimen look like when using a Fluorescence technique?
Shows the locations of specific molecules in the cell by tagging the molecules with fluorescent dyes or antibodies.
How does a Confocal microscope work?
Uses lasers and optics for sectioning fluorescently-stained specimens. Only a single plane of focus is illuminated; out-of-focus fluorescence above and below the plane is subtracted by a computer.
How does electron microscopy differ from light microscopy?
It uses smaller wavelengths to produce a more defined image of smaller objects. It does not use light waves so all images will be in black and white.
Form follows ____
Function
What is cytology?
The study of the microscopic appearance and function of cells, especially for the diagnosis of abnormalities and malignancies.
Name the organelles
Components of a typical animal cell:
- Nucleolus
- Nucleus
- Ribosome (little dots)
- Vesicle
- Rough endoplasmic reticulum
- Golgi apparatus (or “Golgi body”)
- Cytoskeleton
- Smooth endoplasmic reticulum
- Mitochondrion
- Vacuole
- Cytosol (fluid that contains organelles)
- Lysosome
- Centrosome
- Cell membrane
Name the two double membrane bound organelles
Nucleus and mitochondria
Name the single membrane bound organelles
ER, golgi, lysosomes, peroxisomes, phagosomes
Name the organelles not bound by membrane
Nucleolus, ribosomes, cytoskeleton
The polarity of the plasma (cell) membrane can be referred to as _____
Amphipathic
Describe the fluid mosaic model
A model that describes the structure of cell membranes. In this model, a flexible layer made of lipid molecules is interspersed with large protein molecules that act as channels through which other molecules enter and leave the cell.
What surrounds the cell membrane?
The glycocalyx
What creates anchorage for the fluid cell wall?
Junctions and the basement membrane
What are the three types of junctions?
Tight Junctions
Desmosomes
Gap Junctions
What is a tight junction?
The membranes of neighboring cells are very tightly linked to each other
What does a desmosome do?
Function like rivets, fastening cells
together into strong sheets. Intermediate
filaments made of sturdy keratin proteins
anchor desmosomes in the cytoplasm.
What does a gap junction do?
Provide cytoplasmic channels between adjacent cells that are necessary in many types of tissues.
What do the dark and light areas on a nucleus (viewed through an electron microscope) represent?
Euchromatin (light) - diffuse/open/active DNA
Heterochromatin (dark) - dense/coiled/less active DNA
What does the nucleus contain?
DNA, RNA, proteins
What is the main function of the nucleolus?
To make rRNA
What is the function of ribosomes?
Making proteins by linking amino acids together in an order specified by the mRNA.
The smooth ER does what 3 things?
Highly responsible for detoxification
Storage of ions (i.e. Ca in muscle)
Involved in making new membranes
The primary responsibility of the rough ER is ____
The rough ER is located ________
Protein assembly
Near the nucleus and golgi apparatus
The golgi apparatus is primarily responsible for___
Modification and packaging of protiens
Describe the steps in protein synthesis
Transcription: DNA to RNA
Translation: RNA to protein
(ribosome)
(nucleus)
What is the main function of the mitochondria?
What are two processes that carry out this function?
Production of ATP
Citric Acid Cycle and Electron Transport Chain
What are Endosomal compartments?
endosomes, lysosomes, peroxisomes, recycling compartments
What does the cytoskeleton determine?
Cell shape
Locomotion
Provides means of intracellular trafficking
What are the 3 components of the cytoskeleton?
Microfilaments, microtubules and Intermediate fillaments
How are microfilaments (actin/myosin) arranged and what is their purpose:
Parallel arrangement
Motility/trafficking/anchorage (tight/loose junctions)
What is the major component of the mitotic spindle, cilia and flagella?
Microtubules
What are the functions of microtubules?
Intracellular structure, and intracellular transport, as well as ciliary and flagellar motility
What is the function of intermediate filaments?
Architectural support, they do not move
What is the difference between cytoplasm and cytosol?
Cytoplasm includes everything inside the cell with exception of the nucleus in eukaryotic cells.
Cytosal is the fluid outside of nucleus but within the cell membrane.
Name 4 important cell functions
- Protein synthesis (DNA’s role)
- Movement of substances
- Cell division
- Apoptosis and Necrosis
The process of duplicating chromosomes prior to cell division is called ____
DNA replication
What are the 4 enzymes involved in DNA replication and what are their functions?
Helicase: breaks DNA daughter strands and unwinds the helix
Primase: sets RNA primer and recognizes base pairs (A-T, G-C)
DNA polymerase: recognizes primer and builds nucleotides
DNA ligase: joins neighboring strands of DNA
Describe the movement of hydrophobic molecules across the cell membrane
Are lipid soluble and can pass through the membrane rapidly
Describe the movement of polar molecules across the cell membrane
Do not cross the membrane rapidly
Require transport proteins
Describe simple diffusion and name 3 things that affect this process
The movement from high concentration to low concentration.
- Temperature
- Distance
- Size of molecule
How is facilitated diffusion different from simple diffusion?
Can be limited by carrier specificity
May become saturated
May be regulated by hormones or other signals
True or False:
Active Transport is against the concentration gradient and requries energy
True
Endocytosis and Exocytosis are considered to be which type of transport?
Vesicular or Bulk transport
What are the three types of endocytosis and how do they work?
Phagocytosis: “eating”
Pinocytosis: “drinking”
Recptor Mediated: Cell receptors on surface send signal to cell engulf
What are the steps of Mitosis?
Prophase
Metaphase
Anaphase
Telophase
Describe Prophase
Chromatin condences to chromosomes
Spindles form at opposite poles
Nuclear membrane breaks down
Describe Metaphase
Chromosomes align on metaphase plate
Describe Anaphase
Sister chromatids seperate, attach at kinetochore and are pulled toward opposite poles of cell
Describe Telophase
(Identical to Prophase in reverse)
Chromosomes spread out, membranes begin to reform, spindle degenerates
What is the difference between Apoptosis and Cell Necrosis?
Apoptosis:
Programmed cell death, desirable event: leads to refinement of cells
Necrosis:
Cell dies from disease or pathologic cause
